Mobile device and optical imaging lens thereof

ABSTRACT

Present embodiments provide for a mobile device and an optical imaging lens thereof. The optical imaging lens comprises six lens elements positioned sequentially from an object side to an image side. Through controlling the convex or concave shape of the surfaces and/or the refracting power of the lens elements, the optical imaging lens shows better optical characteristics and the total length of the optical imaging lens is shortened.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from P.R.C. Patent Application No. 201310384133.9, filed on Aug. 29, 2013, the contents of which are hereby incorporated by reference in their entirety for all purposes.

TECHNICAL FIELD

The present invention relates to a mobile device and an optical imaging lens thereof, and particularly, relates to a mobile device applying an optical imaging lens having six lens elements and an optical imaging lens thereof.

BACKGROUND

The ever-increasing demand for smaller sized mobile devices, such as cell phones, digital cameras, etc. correspondingly triggered a growing need for a smaller sized photography module, comprising elements such as an optical imaging lens, a module housing unit, and an image sensor, etc., contained therein. Size reductions may be contributed from various aspects of the mobile devices, which includes not only the charge coupled device (CCD) and the complementary metal-oxide semiconductor (CMOS), but also the optical imaging lens mounted therein. When reducing the size of the optical imaging lens, however, achieveing good optical characteristics becomes a challenging problem.

The length of conventional optical imaging lenses comprising four lens elements can be limited in a certain range; however, as the more and more demands in the market for high-end products, high-standard optical imaging lenses which show great quality with more pixels with six lens elements are required. U.S. Pat. Nos. 6,982,834, 6,995,924 and 7,046,452 all disclosed an optical imaging lens constructed with an optical imaging lens having six lens elements, wherein the third lens element has positive refracting power to hinder the shortening of the length of the optical imaging lens, which, from the object-side surface of the first lens element to the image plane, are greater than 10 mm and this is too long for smaller sized mobile devices. Therefore, there is needed to develop optical imaging lens which is capable to place with six lens elements therein, with a shorter length, while also having good optical characters.

SUMMARY

An object of the present invention is to provide a mobile device and an optical imaging lens thereof. With controlling the convex or concave shape of the surfaces and/or the refracting power of the lens elements, the length of the optical imaging lens is shortened and meanwhile the good optical characters, and system functionality are sustained.

In an exemplary embodiment, an optical imaging lens comprises, sequencially from an object side to an image side along an optical axis, comprises an aperture stop, first, second, third, fourth fifth and sixth lens elements, each of the first, second, third, fourth, fifth and sixth lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein: the object-side surface of the first lens element comprises a convex portion in a vicinity of the optical axis; the image-side surface of the second lens element comprises a convex portion in a vicinity of a periphery of the second lens element; the third lens element has negative refracting power, and the image-side surface thereof comprises a concave portion in a vicinity of a periphery of the third lens element; the image-side surface of the fourth lens element comprises a convex portion in a vicinity of the optical axis; and the image-side surface of the sixth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the sixth lens element; the optical imaging lens as a whole comprises only the six lens elements having refracting power.

In another exemplary embodiment, other equation (s), such as those relating to the ratio among parameters could be taken into consideration. For example, an air gap between the first lens element and the second lens element along the optical axis, AG12, an air gap between the second lens element and the third lens element along the optical axis, AG23, an air gap between the fifth lens element and the sixth lens element along the optical axis, AG56, and the sum of the thickness of all six lens elements along the optical axis, ALT, could be controlled to satisfy the equation as follows:

2.0≦ALT/(AG12+AG23+AG56)  Equation (1); or

A central thickness of the second lens element along the optical axis, T2, and a central thickness of the sixth lens element along the optical axis, T6, could be controlled to satisfy the equation as follows:

0.9≦T2/T6  Equation (2); or

AG12, AG23, an air gap between the fourth lens element and the fifth lens element along the optical axis, AG45, and the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis, AAG, could be controlled to satisfy the equation as follows:

2.2≦AAG/(AG12+AG23+AG45)  Equation (3); or

T2 and ALT could be controlled to satisfy the equation as follows:

ALT/T2≦7.0  Equation (4); or

T6 and a central thickness of the third lens element along the optical axis, T3, could be controlled to satisfy the equation as follows:

T6/T3≦2.0  Equation (5); or

T2, AG12, AG23 and AG56 could be controlled to satisfy the equation as follows:

0.7≦T2/(AG12+AG23+AG56)  Equation (6); or

T2 and AAG could be controlled to satisfy the equation as follows:

AAG/T2≦5.0  Equation (7); or

T2 and a central thickness of the first lens element along the optical axis, T1, could be controlled to satisfy the equation as follows:

T1/T2≦1.5  Equation (8); or

AG12, AG45, AG56 and an air gap between the third lens element and the fourth lens element along the optical axis, AG34, could be controlled to satisfy the equation as follows:

1.0≦AG34/(AG12+AG45+AG56)  Equation (9); or

T3, AG12, AG23 and AG45 could be controlled to satisfy the equation as follows:

0.8≦T3/(AG12+AG23+AG45)  Equation (10); or

AG23, AG45, AG56 and AAG could be controlled to satisfy the equation as follows:

2.0≦AAG/(AG23+AG45+AG56)  Equation (11); or

T6, AG12, AG23 and AG45 could be controlled to satisfy the equation as follows:

0.9≦T6/(AG12+AG23+AG45)  Equation (12); or

T3, AG23, AG45 and AG56 could be controlled to satisfy the equation as follows:

0.7≦T3/(AG23+AG45+AG56)  Equation (13); or

T6, AG12, AG23 and AG56 could be controlled to satisfy the equation as follows:

1.0≦T6/(AG12+AG23+AG56)  Equation (14); or

AG12, AG45, AG56 and AAG could be controlled to satisfy the equation as follows:

3.0≦AAG/(AG12+AG45+AG56)  Equation (15).

Aforesaid exemplary embodiments are not limited and could be selectively incorporated in other embodiments described herein.

In some exemplary embodiments, more details about the convex or concave surface structure could be incorporated for one specific lens element or broadly for plural lens elements to enhance the control for the system performance and/or resolution. For example, the object-side surface of the first lens element may comprise a concave portion in a vicinity of a periphery of the first lens element, the object-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis, and/or the object-side surface of the sixth lens element may comprise a concave portion in a vicinity of the optical axis, etc. It is noted that the details listed here could be incorporated in example embodiments if no inconsistency occurs.

In another exemplary embodiment, a mobile device comprising a housing and a photography module positioned in the housing is provided. The photography module comprises any of aforesaid example embodiments of optical imaging lens, a lens barrel, a module housing unit and an image sensor. The lens barrel is for positioning the optical imaging lens, the module housing unit is for positioning the lens barrel, and the image sensor is positioned at the image side of the optical imaging lens.

Through controlling the convex or concave shape of the surfaces and/or the refraction power of the lens element(s), the mobile device and the optical imaging lens thereof in exemplary embodiments achieve good optical characters and effectively shorten the length of the optical imaging lens.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which:

FIG. 1 is a cross-sectional view of one single lens element according to the present disclosure;

FIG. 2 is a cross-sectional view of a first embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 3 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 4 is a table of optical data for each lens element of a first embodiment of an optical imaging lens according to the present disclosure;

FIG. 5 is a table of aspherical data of a first embodiment of the optical imaging lens according to the present disclosure;

FIG. 6 is a cross-sectional view of a second embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 7 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 8 is a table of optical data for each lens element of the optical imaging lens of a second embodiment of the present disclosure;

FIG. 9 is a table of aspherical data of a second embodiment of the optical imaging lens according to the present disclosure;

FIG. 10 is a cross-sectional view of a third embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 11 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a third embodiment of the optical imaging lens according the present disclosure;

FIG. 12 is a table of optical data for each lens element of the optical imaging lens of a third embodiment of the present disclosure;

FIG. 13 is a table of aspherical data of a third embodiment of the optical imaging lens according to the present disclosure;

FIG. 14 is a cross-sectional view of a fourth embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 15 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a fourth embodiment of the optical imaging lens according the present disclosure;

FIG. 16 is a table of optical data for each lens element of the optical imaging lens of a fourth embodiment of the present disclosure;

FIG. 17 is a table of aspherical data of a fourth embodiment of the optical imaging lens according to the present disclosure;

FIG. 18 is a cross-sectional view of a fifth embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 19 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a fifth embodiment of the optical imaging lens according the present disclosure;

FIG. 20 is a table of optical data for each lens element of the optical imaging lens of a fifth embodiment of the present disclosure;

FIG. 21 is a table of aspherical data of a fifth embodiment of the optical imaging lens according to the present disclosure;

FIG. 22 is a cross-sectional view of a sixth embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 23 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a sixth embodiment of the optical imaging lens according the present disclosure;

FIG. 24 is a table of optical data for each lens element of the optical imaging lens of a sixth embodiment of the present disclosure;

FIG. 25 is a table of aspherical data of a sixth embodiment of the optical imaging lens according to the present disclosure;

FIG. 26 is a cross-sectional view of a seventh embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 27 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a seventh embodiment of the optical imaging lens according the present disclosure;

FIG. 28 is a table of optical data for each lens element of the optical imaging lens of a seventh embodiment of the present disclosure;

FIG. 29 is a table of aspherical data of a seventh embodiment of the optical imaging lens according to the present disclosure;

FIG. 30 is a cross-sectional view of an eighth embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 31 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of an eighth embodiment of the optical imaging lens according the present disclosure;

FIG. 32 is a table of optical data for each lens element of the optical imaging lens of an eighth embodiment of the present disclosure;

FIG. 33 is a table of aspherical data of an eighth embodiment of the optical imaging lens according to the present disclosure;

FIG. 34 is a cross-sectional view of a ninth embodiment of an optical imaging lens having six lens elements according to the present disclosure;

FIG. 35 is a chart of longitudinal spherical aberration and other kinds of optical aberrations of a ninth embodiment of the optical imaging lens according the present disclosure;

FIG. 36 is a table of optical data for each lens element of the optical imaging lens of a ninth embodiment of the present disclosure;

FIG. 37 is a table of aspherical data of a ninth embodiment of the optical imaging lens according to the present disclosure;

FIG. 38 is a table for the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) of all nine example embodiments;

FIG. 39 is a structure of an example embodiment of a mobile device;

FIG. 40 is a partially enlarged view of the structure of another example embodiment of a mobile device.

DETAILED DESCRIPTION

For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features. Persons having ordinary skill in the art will understand other varieties for implementing example embodiments, including those described herein. The drawings are not limited to specific scale and similar reference numbers are used for representing similar elements. As used in the disclosures and the appended claims, the terms “example embodiment,” “exemplary embodiment,” and “present embodiment” do not necessarily refer to a single embodiment, although it may, and various example embodiments may be readily combined and interchanged, without departing from the scope or spirit of the present invention. Furthermore, the terminology as used herein is for the purpose of describing example embodiments only and is not intended to be a limitation of the invention. In this respect, as used herein, the term “in” may include “in” and “on”, and the terms “a”, “an” and “the” may include singular and plural references. Furthermore, as used herein, the term “by” may also mean “from”, depending on the context. Furthermore, as used herein, the term “if” may also mean “when” or “upon”, depending on the context. Furthermore, as used herein, the words “and/or” may refer to and encompass any and all possible combinations of one or more of the associated listed items.

Here in the present specification, “a lens element having positive refracting power (or negative refracting power)” means that the lens element has positive refracting power (or negative refracting power) in the vicinity of the optical axis. “An object-side (or image-side) surface of a lens element comprises a convex (or concave) portion in a specific region” means that the object-side (or image-side) surface of the lens element “protrudes outwardly (or depresses inwardly)” along the direction parallel to the optical axis at the specific region, compared with the outer region radially adjacent to the specific region. Taking FIG. 1 for example, the lens element shown therein is radially symmetric around the optical axis which is labeled by I. The object-side surface of the lens element comprises a convex portion at region A, a concave portion at region B, and another convex portion at region C. This is because compared with the outer region radially adjacent to the region A (i.e. region B), the object-side surface protrudes outwardly at the region A, compared with the region C, the object-side surface depresses inwardly at the region B, and compared with the region E, the object-side surface protrudes outwardly at the region C. Here, “in a vicinity of a periphery of a lens element” means that in a vicinity of the peripheral region of a surface for passing imaging light on the lens element, i.e. the region C as shown in FIG. 1. The imaging light comprises chief ray Lc and marginal ray Lm. “In a vicinity of the optical axis” means that in a vicinity of the optical axis of a surface for passing the imaging light on the lens element, i.e. the region A as shown in FIG. 1. Further, a lens element could comprise an extending portion E for mounting the lens element in an optical imaging lens. Ideally, the imaging light would not pass the extending portion E. Here the extending portion E is only for example, the structure and shape thereof are not limited to this specific example. Please also noted that the extending portion of all the lens elements in the example embodiments shown below are skipped for maintaining the drawings clean and concise.

In the present invention, examples of an optical imaging lens which is a prime lens are provided. Example embodiments of an optical imaging lens may comprise a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element, each of the lens elements comprises an object-side surface facing toward an object side and an image-side surface facing toward an image side. These lens elements may be arranged sequencially from the object side to the image side along an optical axis, and example embodiments of the lens as a whole may comprise only the six lens elements having refracting power. In an example embodiment: the object-side surface of the first lens element comprises a convex portion in a vicinity of the optical axis; the image-side surface of the second lens element comprises a convex portion in a vicinity of a periphery of the second lens element; the third lens element has negative refracting power, and the image-side surface thereof comprises a concave portion in a vicinity of a periphery of the third lens element; the image-side surface of the fourth lens element comprises a convex portion in a vicinity of the optical axis; and the image-side surface of the sixth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the sixth lens element.

Preferably, the lens elements are designed in light of the optical characteristics and the length of the optical imaging lens. For example, the first lens element with the convex object-side surface can assist in collecting light, and combining this with the second lens element formed with the convex portion in a vicinity of a periphery of the second lens element on the image-side surface thereof, the third lens element having negative refracting power and formed with the concave portion in a vicinity of a periphery of the third lens element on the image-side surface thereof, the fourth lens element formed with the convex portion in a vicinity of the optical axis on the image-side surface thereof and the sixth lens element formed with the concave portion in a vicinity of the optical axis and the convex portion in a vicinity of a periphery of the sixth lens element on the image-side surface thereof, the aberration of the optical imaging lens could be adjusted. Further with the details of shape on the surfaces of the lens elements listed here, such as the concave portion formed in a vicinity of a periphery of the first lens element on the object-side surface thereof, the concave portion formed in a vicinity of the optical axis on the object-side surface of the fifth lens element and the concave portion formed in a vicinity of the optical axis on the object-side surface of the sixth lens element, the image quality of the optical imaging lens could be further promoted.

In another exemplary embodiment, some equation (s) of parameters, such as those relating to the ratio among parameters could be taken into consideration. For example, an air gap between the first lens element and the second lens element along the optical axis, AG12, an air gap between the second lens element and the third lens element along the optical axis, AG23, an air gap between the fifth lens element and the sixth lens element along the optical axis, AG56, and the sum of the thickness of all six lens elements along the optical axis, ALT, could be controlled to satisfy the equation as follows:

2.0≦ALT/(AG12+AG23+AG56)  Equation (1); or

A central thickness of the second lens element along the optical axis, T2, and a central thickness of the sixth lens element along the optical axis, T6, could be controlled to satisfy the equation as follows:

0.9≦T2/T6  Equation (2); or

AG12, AG23, an air gap between the fourth lens element and the fifth lens element along the optical axis, AG45, and the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis, AAG, could be controlled to satisfy the equation as follows:

2.2≦AAG/(AG12+AG23+AG45)  Equation (3); or

T2 and ALT could be controlled to satisfy the equation as follows:

ALT/T2≦7.0  Equation (4); or

T6 and a central thickness of the third lens element along the optical axis, T3, could be controlled to satisfy the equation as follows:

T6/T3≦2.0  Equation (5); or

T2, AG12, AG23 and AG56 could be controlled to satisfy the equation as follows:

0.7≦T2/(AG12+AG23+AG56)  Equation (6); or

T2 and AAG could be controlled to satisfy the equation as follows:

AAG/T2≦5.0  Equation (7); or

T2 and a central thickness of the first lens element along the optical axis, T1, could be controlled to satisfy the equation as follows:

T1/T2≦1.5  Equation (8); or

AG12, AG45, AG56 and an air gap between the third lens element and the fourth lens element along the optical axis, AG34, could be controlled to satisfy the equation as follows:

1.0≦AG34/(AG12+AG45+AG56)  Equation (9); or

T3, AG12, AG23 and AG45 could be controlled to satisfy the equation as follows:

0.8≦T3/(AG12+AG23+AG45)  Equation (10); or

AG23, AG45, AG56 and AAG could be controlled to satisfy the equation as follows:

2.0≦AAG/(AG23+AG45+AG56)  Equation (11); or

T6, AG12, AG23 and AG45 could be controlled to satisfy the equation as follows:

0.9≦T6/(AG12+AG23+AG45)  Equation (12); or

T3, AG23, AG45 and AG56 could be controlled to satisfy the equation as follows:

0.7≦T3/(AG23+AG45+AG56)  Equation (13); or

T6, AG12, AG23 and AG56 could be controlled to satisfy the equation as follows:

1.0≦T6/(AG12+AG23+AG56)  Equation (14); or

AG12, AG45, AG56 and AAG could be controlled to satisfy the equation as follows:

3.0≦AAG/(AG12+AG45+AG56)  Equation (15).

Aforesaid exemplary embodiments are not limited and could be selectively incorporated in other embodiments described herein.

Reference is now made to Equation (1). Considering shortening of the AG12, AG23 and AG56 has more potential than shortening of ALT, which may face manufacturing difficulties, here ALT/(AG12+AG23+AG56) is designed for assisting shortening the length of the optical imaging lens. The value of ALT/(AG12+AG23+AG56) is suggested for a lower limit, such as 2.0 to satisfying Equation (1), and preferably, it is suggested to be within 2.0˜20.0.

Reference is now made to Equation (2). Considering the configuration between the thickness of the second and sixth lens elements to avoid any extremely thin or thick lens element, and balancing optical characters and manufacturing difficulty, here the value of T2/T6 is suggested for a lower limit, 0.9 to satisfying Equation (2), and preferably, it is suggested to be within 0.9˜3.0.

Reference is now made to Equations (3), (11) and (15). Considering the shortening of the air gap other than AG34, i.e. AG12, AG23, AG45 and AG56, has more potential for the negative refracting power of the third lens element which requires a certain distance for the air gap between the third and fourth lens elements to disperse the light onto a desirable level when entering into the fourth lens element, here AAG/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56) and AAG/(AG12+AG45+AG56) are designed for assisting shortening the length of the optical imaging lens and promoting the imaging quality. The value of AAG/(AG12+AG23+AG45) is suggested for a lower limit, such as 2.2 to satisfying Equation (3), and preferably, it is suggested to be within 2.2˜6.0. The value of AAG/(AG23+AG45+AG56) is suggested for a lower limit, such as 2.0 to satisfying Equation (11), and preferably, it is suggested to be within 2.0˜8.0. The value of AAG/(AG12+AG45+AG56) is suggested for a lower limit, such as 3.0 to satisfying Equation (15), and preferably, it is suggested to be within 3.0˜6.0.

Reference is now made to Equations (4). As mentioned before, the shortening of the air gaps adjacent to the second lens element, i.e. AG12 and AG23, are desirable, but this makes the thickness of the second lens element expands in ratio. Therefore, for shortening the length of the optical imaging lens, the value of ALT/T2 is suggested for an upper limit, such as 7.0 to satisfy Equation (5), and preferably, it is suggested to be within 4.5˜7.0.

Reference is now made to Equation (5). Considering the configuration between the thickness of the third and sixth lens elements to avoid any extremely thin or thick lens element, and balancing optical characters and manufacturing difficulty, here the value of T6/T3 is suggested for an upper limit, 2.0 to satisfying Equation (5), and preferably, it is suggested to be within 0.4˜2.0.

Reference is now made to Equations (6), (9), (10), (12), (13) and (14). As mentioned before, the shortening of the air gap other than AG34, i.e. AG12, AG23, AG45 and AG56, has more potential, and this makes the values of T2/(AG12+AG23+AG56), AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56) and T6/(AG12+AG23+AG56) are suggested for a lower limit. Here, the value of T2/(AG12+AG23+AG56) is suggested to be greater than or equal to 0.7 to satisfy Equation (6), and preferably, it is suggested to be within 0.7˜2.5; the value of AG34/(AG12+AG45+AG56) is suggested to be greater than or equal to 1.0 to satisfy Equation (9), and preferably, it is suggested to be within 1.0˜5.0; the value of T3/(AG12+AG23+AG45) is suggested to be greater than or equal to 0.8 to satisfy Equation (10), and preferably, it is suggested to be within 0.8˜2.5; the value of T6/(AG12+AG23+AG45) is suggested to be greater than or equal to 0.9 to satisfy Equation (12), and preferably, it is suggested to be within 0.9˜3.0; the value of T3/(AG23+AG45+AG56) is suggested to be greater than or equal to 0.7 to satisfy Equation (13), and preferably, it is suggested to be within 0.7˜2.5; and the value of T6/(AG12+AG23+AG56) is suggested to be greater than or equal to 1.0 to satisfy Equation (14), and preferably, it is suggested to be within 1.0˜3.0.

Reference is now made to Equations (7) and (8). As mentioned above, the thickness of the second lens element is required for a certain value, but the value of both AAG and T1 could be shortened with more potential. Therefore, here the value of AAG/T2 is suggested to be smaller than or equal to 5.0 to satisfy Equation (7), and preferably, it is suggested to be within 1.5˜5.0; and the value of T1/T2 is suggested to be smaller than or equal to 1.5 to satisfy Equation (8), and preferably, it is suggested to be within 0.8˜1.5.

When implementing example embodiments, more details about the convex or concave surface structure may be incorporated for one specific lens element or broadly for plural lens elements to enhance the control for the system performance and/or resolution, as illustrated in the following embodiments. For example, the object-side surface of the first lens element may comprise a concave portion in a vicinity of a periphery of the first lens element, the object-side surface of the fifth lens element comprises a concave portion in a vicinity of the optical axis, and/or the object-side surface of the sixth lens element may comprise a concave portion in a vicinity of the optical axis, etc. It is noted that the details listed here could be incorporated in example embodiments if no inconsistency occurs.

Several exemplary embodiments and associated optical data will now be provided for illustrating example embodiments of optical imaging lens with good optical characters and a shortened length. Reference is now made to FIGS. 2-5. FIG. 2 illustrates an example cross-sectional view of an optical imaging lens 1 having six lens elements of the optical imaging lens according to a first example embodiment. FIG. 3 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 1 according to an example embodiment. FIG. 4 illustrates an example table of optical data of each lens element of the optical imaging lens 1 according to an example embodiment. FIG. 5 depicts an example table of aspherical data of the optical imaging lens 1 according to an example embodiment.

As shown in FIG. 2, the optical imaging lens 1 of the present embodiment comprises, in order from an object side A1 to an image side A2 along an optical axis, an aperture stop 100, a first lens element 110, a second lens element 120, a third lens element 130, a fourth lens element 140, a fifth lens element 150 and a sixth lens element 16. A filtering unit 170 and an image plane 180 of an image sensor are positioned at the image side A2 of the optical lens 1. Each of the first, second, third, fourth, fifth, sixth lens elements 110, 120, 130, 140, 150, 160 and the filtering unit 170 comprises an object-side surface 111/121/131/141/151/161/171 facing toward the object side A1 and an image-side surface 112/122/132/142/152/162/172 facing toward the image side A2. The example embodiment of the filtering unit 170 illustrated is an IR cut filter (infrared cut filter) positioned between the sixth lens element 160 and an image plane 180. The filtering unit 170 selectively absorbs light with specific wavelength from the light passing optical imaging lens 1. For example, IR light is absorbed, and this will prohibit the IR light which is not seen by human eyes from producing an image on the image plane 180.

Please noted that during the normal operation of the optical imaging lens 1, the distance between any two adjacent lens elements of the first, second, third, fourth, fifth, and sixth lens elements 110, 120, 130, 140, 150, 160 is a unchanged value, i.e. the optical imaging lens 1 is a prime lens.

Exemplary embodiments of each lens element of the optical imaging lens 1 which may be constructed by plastic material will now be described with reference to the drawings.

An example embodiment of the first lens element 110 may have positive refracting power. The object-side surface 111 comprises a convex portion 1111 in a vicinity of the optical axis and a concave portion 1112 in a vicinity of a periphery of the first lens element 110. The image-side surface 112 is a convex surface.

An example embodiment of the second lens element 120 may have positive refracting power. The object-side surface 121 comprises a concave portion 1211 in a vicinity the optical axis and a convex portion 1212 in a vicinity of a periphery of the second lens element 120. The image-side surface 122 is a convex surface comprising a convex portion 1221 in a vicinity of a periphery of the second lens element 120.

An example embodiment of the third lens element 130 may have negative refracting power. The object-side surface 131 and image-side surface 132 are both concave surfaces. The image-side surface 132 comprises a concave portion 1321 in a vicinity of a periphery of the third lens element 130.

An example embodiment of the fourth lens element 140 may have positive refracting power. The object-side surface 141 is a concave surface and the image-side surface 142 is a convex surface comprising a convex portion 1421 in a vicinity of the optical axis.

An example embodiment of the fifth lens element 150 may have positive refracting power. The object-side surface 151 is a concave surface comprising a concave portion 1511 in a vicinity of the optical axis. The image-side surface 152 is a convex surface.

An example embodiment of the sixth lens element 160 may have negative refracting power. The object-side surface 161 comprises a concave portion 1611 in a vicinity of the optical axis and a convex portion 1612 in a vicinity of a periphery of the sixth lens element 160. The image-side surface 162 comprises a concave portion 1621 in a vicinity of the optical axis and a convex portion 1622 in a vicinity of a periphery of the sixth lens element 160.

In example embodiments, air gaps exist between the lens elements 110, 120, 130, 140, 150, 160, the filtering unit 170 and the image plane 180 of the image sensor. For example, FIG. 1 illustrates the air gap d1 existing between the first lens element 110 and the second lens element 120, the air gap d2 existing between the second lens element 120 and the third lens element 130, the air gap d3 existing between the third lens element 130 and the fourth lens element 140, the air gap d4 existing between the fourth lens element 140 and the fifth lens element 150, the air gap d5 existing between the fifth lens element 150 and the sixth lens element 160, the air gap d6 existing between the sixth lens element 160 and the filtering unit 170 and the air gap d7 existing between the filtering unit 170 and the image plane 180 of the image sensor. However, in other embodiments, any of the aforesaid air gaps may or may not exist. For example, the profiles of opposite surfaces of any two adjacent lens elements may correspond to each other, and in such situation, the air gap may not exist. The air gap d1 is denoted by AG12, the air gap d2 is denoted by AG23, the air gap d3 is denoted by AG34, the air gap d4 is denoted by AG45, the air gap d5 is denoted by AG56, and the sum of all air gaps d1, d2, d3, d4 and d5 between the first and sixth lens elements 110, 160 is denoted by AAG.

FIG. 4 depicts the optical characters of each lens elements in the optical imaging lens 1 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.243 (mm);     -   AAG=0.976 (mm);     -   ALT/(AG12+AG23+AG56)=14.080;     -   T2/T6=1.061;     -   AAG/(AG12+AG23+AG45)=4.781;     -   ALT/T2=6.990;     -   T6/T3=1.228;     -   T2/(AG12+AG23+AG56)=2.014;     -   AAG/T2=2.103;     -   T1/T2=1.213;     -   AG34/(AG12+AG45+AG56)=3.387;     -   T3/(AG12+AG23+AG45)=1.745;     -   AAG/(AG23+AG45+AG56)=4.560;     -   T6/(AG12+AG23+AG45)=2.142;     -   T3/(AG23+AG45+AG56)=1.664;     -   T6/(AG12+AG23+AG56)=1.898;     -   AAG/(AG12+AG45+AG56)=4.779;     -   wherein the distance from the object-side surface 111 of the         first lens element 110 to the image plane 180 along the optical         axis is 5.552 mm, and the length of the optical imaging lens 1         is shortened.

The aspherical surfaces, including the object-side surface 111 and the image-side surface 112 of the first lens element 110, the object-side surface 121 and the image-side surface 122 of the second lens element 120, the object-side surface 131 and the image-side surface 132 of the third lens element 130, the object-side surface 141 and the image-side surface 142 of the fourth lens element 140, the object-side surface 151 and the image-side surface 152 of the fifth lens element 150 and the object-side surface 161 and the image-side surface 162 of the sixth lens element 160 are all defined by the following aspherical formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{i = 1}^{n}{a_{i} \times Y^{i}}}}$

wherein,

R represents the radius of curvature of the surface of the lens element;

Z represents the depth of the aspherical surface (the perpendicular distance between the point of the aspherical surface at a distance Y from the optical axis and the tangent plane of the vertex on the optical axis of the aspherical surface);

Y represents the perpendicular distance between the point of the aspherical surface and the optical axis;

K represents a conic constant;

a_(i) represents an aspherical coefficient of i^(th) level.

The values of each aspherical parameter are shown in FIG. 5.

As illustrated in FIG. 3, longitudinal spherical aberration (a), the curves of different wavelengths are closed to each other. This represents off-axis light with respect to these wavelengths is focused around an image point. From the vertical deviation of each curve shown therein, the offset of the off-axis light relative to the image point is within ±0.02 mm. Therefore, the present embodiment improves the longitudinal spherical aberration with respect to different wavelengths.

Please refer to FIG. 3, astigmatism aberration in the sagittal direction (b) and astigmatism aberration in the tangential direction (c). The focus variation with respect to the three wavelengths in the whole field falls within ±0.20 mm. This reflects the optical imaging lens 1 of the present embodiment eliminates aberration effectively. Additionally, the closed curves represents dispersion is improved.

Please refer to FIG. 3, distortion aberration (d), which showing the variation of the distortion aberration is within ±1.0%. Such distortion aberration meets the requirement of acceptable image quality and shows the optical imaging lens 1 of the present embodiment could restrict the distortion aberration to raise the image quality even though the length of the optical imaging lens 1 is shortened to 5.552 mm.

Therefore, the optical imaging lens 1 of the present embodiment shows great characteristics in the longitudinal spherical aberration, astigmatism in the sagittal direction, astigmatism in the tangential direction, and distortion aberration. According to above illustration, the optical imaging lens 1 of the example embodiment indeed achieves great optical performance and the length of the optical imaging lens 1 is effectively shortened.

Reference is now made to FIGS. 6-9. FIG. 6 illustrates an example cross-sectional view of an optical imaging lens 2 having six lens elements of the optical imaging lens according to a second example embodiment. FIG. 7 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 2 according to the second example embodiment. FIG. 8 shows an example table of optical data of each lens element of the optical imaging lens 2 according to the second example embodiment. FIG. 9 shows an example table of aspherical data of the optical imaging lens 2 according to the second example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 2, for example, reference number 231 for labeling the object-side surface of the third lens element 230, reference number 232 for labeling the image-side surface of the third lens element 230, etc.

As shown in FIG. 6, the optical imaging lens 2 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 200, a first lens element 210, a second lens element 220, a third lens element 230, a fourth lens element 240, a fifth lens element 250 and a sixth lens element 260.

The differences between the second embodiment and the first embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 210, 220, 230, 240, 250, 260 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 211, 221, 231, 241, 251, 261 facing to the object side A1 and the image-side surfaces 212, 222, 232, 242, 252, 262 facing to the image side A2, are similar to those in the first embodiment. Please refer to FIG. 8 for the optical characteristics of each lens elements in the optical imaging lens 2 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.210 (mm);     -   AAG=1.013 (mm);     -   ALT/(AG12+AG23+AG56)=13.498;     -   T2/T6=1.076;     -   AAG/(AG12+AG23+AG45)=4.096;     -   ALT/T2=6.989;     -   T6/T3=1.221;     -   T2/(AG12+AG23+AG56)=1.931;     -   AAG/T2=2.205;     -   T1/T2=1.222;     -   AG34/(AG12+AG45+AG56)=2.863;     -   T3/(AG12+AG23+AG45)=1.413;     -   AAG/(AG23+AG45+AG56)=3.937;     -   T6/(AG12+AG23+AG45)=1.726;     -   T3/(AG23+AG45+AG56)=1.358;     -   T6/(AG12+AG23+AG56)=1.794;     -   AAG/(AG12+AG45+AG56)=4.229;     -   wherein the distance from the object-side surface 211 of the         first lens element 210 to the image plane 280 along the optical         axis is 5.555 mm and the length of the optical imaging lens 2 is         shortened.

As shown in FIG. 7, the optical imaging lens 2 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 2 is effectively shortened.

Reference is now made to FIGS. 10-13. FIG. 10 illustrates an example cross-sectional view of an optical imaging lens 3 having six lens elements of the optical imaging lens according to a third example embodiment. FIG. 11 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 3 according to the third example embodiment. FIG. 12 shows an example table of optical data of each lens element of the optical imaging lens 3 according to the third example embodiment. FIG. 13 shows an example table of aspherical data of the optical imaging lens 3 according to the third example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 3, for example, reference number 331 for labeling the object-side surface of the third lens element 330, reference number 332 for labeling the image-side surface of the third lens element 330, etc.

As shown in FIG. 10, the optical imaging lens 3 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 300, a first lens element 310, a second lens element 320, a third lens element 330, a fourth lens element 340, a fifth lens element 350 and a sixth lens element 360.

The differences between the third embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the surface shape of the object-side surface 321, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 310, 320, 330, 340, 350, 360 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 311, 331, 341, 351, 361 facing to the object side A1 and the image-side surfaces 312, 322, 332, 342, 352, 362 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surface 321 of the second lens element 320 is a concave surface comprising a concave portion 3211 in a vicinity of the optical axis and a concave portion 3212 in a vicinity of a periphery of the second lens element 320. Please refer to FIG. 12 for the optical characteristics of each lens elements in the optical imaging lens 3 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.067 (mm);     -   AAG=1.112 (mm);     -   ALT/(AG12+AG23+AG56)=10.000;     -   T2/T6=1.148;     -   AAG/(AG12+AG23+AG45)=4.884;     -   ALT/T2=6.927;     -   T6/T3=1.152;     -   T2/(AG12+AG23+AG56)=1.444;     -   AAG/T2=2.511;     -   T1/T2=1.257;     -   AG34/(AG12+AG45+AG56)=2.732;     -   T3/(AG12+AG23+AG45)=1.471;     -   AAG/(AG23+AG45+AG56)=3.834;     -   T6/(AG12+AG23+AG45)=1.694;     -   T3/(AG23+AG45+AG56)=1.154;     -   T6/(AG12+AG23+AG56)=1.257;     -   AAG/(AG12+AG45+AG56)=4.072;     -   wherein the distance from the object-side surface 311 of the         first lens element 310 to the image plane 380 along the optical         axis is 5.415 mm and the length of the optical imaging lens 3 is         shortened.

As shown in FIG. 11, the optical imaging lens 3 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 3 is effectively shortened.

Reference is now made to FIGS. 14-17. FIG. 14 illustrates an example cross-sectional view of an optical imaging lens 4 having six lens elements of the optical imaging lens according to a fourth example embodiment. FIG. 15 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 4 according to the fourth embodiment. FIG. 16 shows an example table of optical data of each lens element of the optical imaging lens 4 according to the fourth example embodiment. FIG. 17 shows an example table of aspherical data of the optical imaging lens 4 according to the fourth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 4, for example, reference number 431 for labeling the object-side surface of the third lens element 430, reference number 432 for labeling the image-side surface of the third lens element 430, etc.

As shown in FIG. 14, the optical imaging lens 4 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 400, a first lens element 410, a second lens element 420, a third lens element 430, a fourth lens element 440, a fifth lens element 450 and a sixth lens element 460.

The differences between the fourth embodiment and the first embodiment are the radius of curvature and thickness of each lens element and the distance of each air gap, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 410, 420, 430, 440, 450, 460 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 411, 421, 431, 441, 451, 461 facing to the object side A1 and the image-side surfaces 412, 422, 432, 442, 452, 462 facing to the image side A2, are similar to those in the first embodiment. Please refer to FIG. 16 for the optical characteristics of each lens elements in the optical imaging lens 4 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.230 (mm);     -   AAG=1.091 (mm);     -   ALT/(AG12+AG23+AG56)=9.770;     -   T2/T6=1.454;     -   AAG/(AG12+AG23+AG45)=4.000;     -   ALT/T2=6.990;     -   T6/T3=0.704;     -   T2/(AG12+AG23+AG56)=1.398;     -   AAG/T2=2.361;     -   T1/T2=1.209;     -   AG34/(AG12+AG45+AG56)=1.821;     -   T3/(AG12+AG23+AG45)=1.655;     -   AAG/(AG23+AG45+AG56)=3.087;     -   T6/(AG12+AG23+AG45)=1.165;     -   T3/(AG23+AG45+AG56)=1.277;     -   T6/(AG12+AG23+AG56)=0.961;     -   AAG/(AG12+AG45+AG56)=3.044;     -   wherein the distance from the object-side surface 411 of the         first lens element 410 to the image plane 480 along the optical         axis is 5.525 mm and the length of the optical imaging lens 4 is         shortened.

As shown in FIG. 15, the optical imaging lens 4 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 4 is effectively shortened.

Reference is now made to FIGS. 18-21. FIG. 18 illustrates an example cross-sectional view of an optical imaging lens 5 having six lens elements of the optical imaging lens according to a fifth example embodiment. FIG. 19 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 5 according to the fifth embodiment. FIG. 20 shows an example table of optical data of each lens element of the optical imaging lens 5 according to the fifth example embodiment. FIG. 21 shows an example table of aspherical data of the optical imaging lens 5 according to the fifth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 5, for example, reference number 531 for labeling the object-side surface of the third lens element 530, reference number 532 for labeling the image-side surface of the third lens element 530, etc.

As shown in FIG. 18, the optical imaging lens 5 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 500, a first lens element 510, a second lens element 520, a third lens element 530, a fourth lens element 540, a fifth lens element 550 and a sixth lens element 560.

The differences between the fifth embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the spherical surface shape of the object-side surface 511, 521, 531, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 510, 520, 530, 540, 550, 560 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 541, 551, 561 facing to the object side A1 and the image-side surfaces 512, 522, 532, 542, 552, 562 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surface 511 of the first lens element 510 is a convex surface, the object-side surface 521 of the second lens element 520 is a concave surface, and the object-side surface 531 of the third lens element 530 comprises a convex portion 5311 in a vicinity of the optical axis and a concave portion 5312 in a vicinity of a periphery of the third lens element 530. Please refer to FIG. 20 for the optical characteristics of each lens elements in the optical imaging lens 5 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=2.998 (mm);     -   AAG=0.993 (mm);     -   ALT/(AG12+AG23+AG56)=14.035;     -   T2/T6=0.826;     -   AAG/(AG12+AG23+AG45)=4.651;     -   ALT/T2=7.595;     -   T6/T3=1.650;     -   T2/(AG12+AG23+AG56)=1.848;     -   AAG/T2=2.517;     -   T1/T2=1.397;     -   AG34/(AG12+AG45+AG56)=3.982;     -   T3/(AG12+AG23+AG45)=1.355;     -   AAG/(AG23+AG45+AG56)=6.719;     -   T6/(AG12+AG23+AG45)=2.237;     -   T3/(AG23+AG45+AG56)=1.958;     -   T6/(AG12+AG23+AG56)=2.237;     -   AAG/(AG12+AG45+AG56)=5.347;     -   wherein the distance from the object-side surface 511 of the         first lens element 510 to the image plane 580 along the optical         axis is 5.309 mm and the length of the optical imaging lens 5 is         shortened.

As shown in FIG. 19, the optical imaging lens 5 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 5 is effectively shortened.

Reference is now made to FIGS. 22-25. FIG. 22 illustrates an example cross-sectional view of an optical imaging lens 6 having six lens elements of the optical imaging lens according to a sixth example embodiment. FIG. 23 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 6 according to the sixth embodiment. FIG. 24 shows an example table of optical data of each lens element of the optical imaging lens 6 according to the sixth example embodiment. FIG. 25 shows an example table of aspherical data of the optical imaging lens 6 according to the sixth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 6, for example, reference number 631 for labeling the object-side surface of the third lens element 630, reference number 632 for labeling the image-side surface of the third lens element 630, etc.

As shown in FIG. 22, the optical imaging lens 6 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 600, a first lens element 610, a second lens element 620, a third lens element 630, a fourth lens element 640, a fifth lens element 650 and a sixth lens element 660.

The differences between the sixth embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of object-side surfaces 611, 651, 661 and image-side surface 652, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 610, 620, 630, 640, 650, 660 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 621, 631, 641 facing to the object side A1 and the image-side surfaces 612, 622, 632, 642, 662 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surfaces 611 of the first lens element 610 is a convex surface; the object-side surfaces 651 of the fifth lens element 650 comprises a convex portion 6511 in a vicinity of the optical axis and a concave portion 6512 in a vicinity of a periphery of the fifth lens element 650; the image-side surfaces 652 of the fifth lens element 650 comprises a convex portion 6521 in a vicinity of the optical axis, a convex portion 6522 in a vicinity of a periphery of the fifth lens element 650 and a concave portion 6523 between the vicinity of the optical axis and the vicinity of the periphery of the fifth lens element 650; the object-side surfaces 661 of the sixth lens element 660 is a concave surface comprising a concave portion 6611 in a vicinity of a periphery of the sixth lens element 660. Please refer to FIG. 24 for the optical characteristics of each lens elements in the optical imaging lens 6 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.114 (mm);     -   AAG=1.873 (mm);     -   ALT/(AG12+AG23+AG56)=3.698;     -   T2/T6=2.266;     -   AAG/(AG12+AG23+AG45)=2.985;     -   ALT/T2=6.884;     -   T6/T3=0.738;     -   T2/(AG12+AG23+AG56)=0.537;     -   AAG/T2=4.141;     -   T1/T2=1.187;     -   AG34/(AG12+AG45+AG56)=0.439;     -   T3/(AG12+AG23+AG45)=0.431;     -   AAG/(AG23+AG45+AG56)=1.480;     -   T6/(AG12+AG23+AG45)=0.318;     -   T3/(AG23+AG45+AG56)=0.214;     -   T6/(AG12+AG23+AG56)=0.237;     -   AAG/(AG12+AG45+AG56)=1.504;     -   wherein the distance from the object-side surface 611 of the         first lens element 610 to the image plane 680 along the optical         axis is 5.940 mm and the length of the optical imaging lens 6 is         shortened.

As shown in FIG. 23, the optical imaging lens 6 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 6 is effectively shortened.

Reference is now made to FIGS. 26-29. FIG. 26 illustrates an example cross-sectional view of an optical imaging lens 7 having six lens elements of the optical imaging lens according to a seventh example embodiment. FIG. 27 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 7 according to the seventh embodiment. FIG. 28 shows an example table of optical data of each lens element of the optical imaging lens 7 according to the seventh example embodiment. FIG. 29 shows an example table of aspherical data of the optical imaging lens 7 according to the seventh example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 7, for example, reference number 731 for labeling the object-side surface of the third lens element 730, reference number 732 for labeling the image-side surface of the third lens element 730, etc.

As shown in FIG. 26, the optical imaging lens 7 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 700, a first lens element 710, a second lens element 720, a third lens element 730, a fourth lens element 740, a fifth lens element 750 and a sixth lens element 760.

The differences between the seventh embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of the object-side surfaces 721, 751 and the object-side surfaces 732, 752, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 710, 720, 730, 740, 750, 760 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 711, 731, 741, 761 facing to the object side A1 and the image-side surfaces 712, 722, 742, 762 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surfaces 721 of the second lens element 720 is a concave surface; the image-side surfaces 732 of the third lens element 730 comprises a concave portion 7321 in a vicinity of the optical axis, a concave portion 7322 in a vicinity of a periphery of the third lens element 730 and a convex portion 7323 between the vicinity of the optical axis and the vicinity of the periphery of the third lens element 730; the object-side surfaces 751 of the fifth lens element 750 comprises a concave portion 7511 in a vicinity of the optical axis, a concave portion 7512 in a vicinity of a periphery of the fifth lens element 750 and a convex portion 7513 between the vicinity of the optical axis and the vicinity of the periphery of the fifth lens element 750; the image-side surfaces 752 of the fifth lens element 750 comprises a convex portion 7521 in a vicinity of the optical axis, a convex portion 7522 in a vicinity of a periphery of the fifth lens element 750 and a concave portion 7523 between the vicinity of the optical axis and the vicinity of the periphery of the fifth lens element 750. Please refer to FIG. 28 for the optical characteristics of each lens elements in the optical imaging lens 7 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=2.913 (mm);     -   AAG=1.500 (mm);     -   ALT/(AG12+AG23+AG56)=7.447;     -   T2/T6=1.575;     -   AAG/(AG12+AG23+AG45)=3.027;     -   ALT/T2=6.849;     -   T6/T3=0.649;     -   T2/(AG12+AG23+AG56)=1.087;     -   AAG/T2=3.526;     -   T1/T2=1.401;     -   AG34/(AG12+AG45+AG56)=1.386;     -   T3/(AG12+AG23+AG45)=0.839;     -   AAG/(AG23+AG45+AG56)=2.556;     -   T6/(AG12+AG23+AG45)=0.545;     -   T3/(AG23+AG45+AG56)=0.709;     -   T6/(AG12+AG23+AG56)=0.690;     -   AAG/(AG12+AG45+AG56)=2.556;     -   wherein the distance from the object-side surface 711 of the         first lens element 710 to the image plane 780 along the optical         axis is 5.645 mm and the length of the optical imaging lens 7 is         shortened.

As shown in FIG. 27, the optical imaging lens 7 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 7 is effectively shortened.

Reference is now made to FIGS. 30-33. FIG. 30 illustrates an example cross-sectional view of an optical imaging lens 8 having six lens elements of the optical imaging lens according to an eighth example embodiment. FIG. 31 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 8 according to the eighth embodiment. FIG. 32 shows an example table of optical data of each lens element of the optical imaging lens 8 according to the eighth example embodiment. FIG. 33 shows an example table of aspherical data of the optical imaging lens 8 according to the eighth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 8, for example, reference number 831 for labeling the object-side surface of the third lens element 830, reference number 832 for labeling the image-side surface of the third lens element 830, etc.

As shown in FIG. 30, the optical imaging lens 8 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 800, a first lens element 810, a second lens element 820, a third lens element 830, a fourth lens element 840, a fifth lens element 850 and a sixth lens element 860.

The differences between the eighth embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of the object-side surfaces 811, 821, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 810, 820, 830, 840, 850, 860 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 831, 841, 851, 861 facing to the object side A1 and the image-side surfaces 812, 822, 832, 842, 852, 862 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surfaces 811 of the first lens element 810 is a convex surface and the object-side surfaces 821 of the second lens element 820 is a concave surface. Please refer to FIG. 32 for the optical characteristics of each lens elements in the optical imaging lens 8 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.307 (mm);     -   AAG=1.090 (mm);     -   ALT/(AG12+AG23+AG56)=9.809;     -   T2/T6=1.271;     -   AAG/(AG12+AG23+AG45)=2.739;     -   ALT/T2=7.000;     -   T6/T3=0.845;     -   T2/(AG12+AG23+AG56)=1.401;     -   AAG/T2=2.307;     -   T1/T2=1.234;     -   AG34/(AG12+AG45+AG56)=1.275;     -   T3/(AG12+AG23+AG45)=1.105;     -   AAG/(AG23+AG45+AG56)=2.505;     -   T6/(AG12+AG23+AG45)=0.934;     -   T3/(AG23+AG45+AG56)=1.010;     -   T6/(AG12+AG23+AG56)=1.102;     -   AAG/(AG12+AG45+AG56)=2.505;     -   wherein the distance from the object-side surface 811 of the         first lens element 810 to the image plane 880 along the optical         axis is 5.621 mm and the length of the optical imaging lens 8 is         shortened.

As shown in FIG. 31, the optical imaging lens 8 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 8 is effectively shortened.

Reference is now made to FIGS. 34-37. FIG. 34 illustrates an example cross-sectional view of an optical imaging lens 9 having six lens elements of the optical imaging lens according to a ninth example embodiment. FIG. 35 shows example charts of longitudinal spherical aberration and other kinds of optical aberrations of the optical imaging lens 9 according to the ninth embodiment. FIG. 36 shows an example table of optical data of each lens element of the optical imaging lens 9 according to the ninth example embodiment. FIG. 37 shows an example table of aspherical data of the optical imaging lens 9 according to the ninth example embodiment. The reference numbers labeled in the present embodiment are similar to those in the first embodiment for the similar elements, but here the reference numbers are initialed with 9, for example, reference number 931 for labeling the object-side surface of the third lens element 930, reference number 932 for labeling the image-side surface of the third lens element 930, etc.

As shown in FIG. 34, the optical imaging lens 9 of the present embodiment, in an order from an object side A1 to an image side A2 along an optical axis, comprises an aperture stop 900, a first lens element 910, a second lens element 920, a third lens element 930, a fourth lens element 940, a fifth lens element 950 and a sixth lens element 960.

The differences between the ninth embodiment and the first embodiment are the radius of curvature and thickness of each lens element, the distance of each air gap and the configuration of the concave/convex shape of the object-side surfaces 921, 961 and the object-side surfaces 932, 952, but the configuration of the positive/negative refracting power of the first, second, third, fourth, fifth and sixth lens elements 910, 920, 930, 940, 950, 960 and configuration of the concave/convex shape of surfaces, comprising the object-side surfaces 911, 931, 941, 951 facing to the object side A1 and the image-side surfaces 912, 922, 942, 962 facing to the image side A2, are similar to those in the first embodiment. Specifically, the object-side surfaces 921 of the second lens element 920 is a concave surface; the image-side surfaces 932 of the third lens element 930 comprises a concave portion 9321 in a vicinity of the optical axis, a concave portion 9322 in a vicinity of a periphery of the third lens element 930 and a convex portion 9323 between the vicinity of the optical axis and the vicinity of the periphery of the third lens element 930; the image-side surfaces 952 of the fifth lens element 950 comprises a convex portion 9521 in a vicinity of the optical axis, a convex portion 9522 in a vicinity of a periphery of the fifth lens element 950 and a concave portion 9523 between the vicinity of the optical axis and the vicinity of the periphery of the fifth lens element 950; the object-side surface 961 of the sixth lens element 960 is a concave surface comprising a concave portion 9611 in a vicinity of a periphery of the sixth lens element 960. Please refer to FIG. 36 for the optical characteristics of each lens elements in the optical imaging lens 9 of the present embodiment, wherein the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) are:

-   -   ALT=3.057 (mm);     -   AAG=1.542 (mm);     -   ALT/(AG12+AG23+AG56)=5.392;     -   T2/T6=1.230;     -   AAG/(AG12+AG23+AG45)=4.347;     -   ALT/T2=5.937;     -   T6/T3=1.155;     -   T2/(AG12+AG23+AG56)=0.908;     -   AAG/T2=2.995;     -   T1/T2=1.164;     -   AG34/(AG12+AG45+AG56)=1.320;     -   T3/(AG12+AG23+AG45)=1.022;     -   AAG/(AG23+AG45+AG56)=2.480;     -   T6/(AG12+AG23+AG45)=1.180;     -   T3/(AG23+AG45+AG56)=0.583;     -   T6/(AG12+AG23+AG56)=0.738;     -   AAG/(AG12+AG45+AG56)=2.480;     -   wherein the distance from the object-side surface 911 of the         first lens element 910 to the image plane 980 along the optical         axis is 5.654 mm and the length of the optical imaging lens 9 is         shortened.

As shown in FIG. 35, the optical imaging lens 9 of the present embodiment shows great characteristics in longitudinal spherical aberration (a), astigmatism in the sagittal direction (b), astigmatism in the tangential direction (c), and distortion aberration (d). Therefore, according to the above illustration, the optical imaging lens of the present embodiment indeed shows great optical performance and the length of the optical imaging lens 9 is effectively shortened.

Please refer to FIG. 38, which shows the values of ALT, AAG, ALT/(AG12+AG23+AG56), T2/T6, AAG/(AG12+AG23+AG45), ALT/T2, T6/T3, T2/(AG12+AG23+AG56), AAG/T2, T1/T2, AG34/(AG12+AG45+AG56), T3/(AG12+AG23+AG45), AAG/(AG23+AG45+AG56), T6/(AG12+AG23+AG45), T3/(AG23+AG45+AG56), T6/(AG12+AG23+AG56) and AAG/(AG12+AG45+AG56) of all nine embodiments, and it is clear that the optical imaging lens of the present invention satisfy the Equations (1), (2), (3), (4), (5), (6), (7), (8), (9), (10, (11), (12), (13), (14) and/or (15).

Reference is now made to FIG. 39, which illustrates an example structural view of a first embodiment of mobile device 20 applying an aforesaid optical imaging lens. The mobile device 20 comprises a housing 21 and a photography module 22 positioned in the housing 21. Examples of the mobile device 20 may be, but are not limited to, a mobile phone, a camera, a tablet computer, a personal digital assistant (PDA), etc.

As shown in FIG. 39, the photography module 22 may comprise an aforesaid optical imaging lens with six lens elements, which is a prime lens and for example the optical imaging lens 1 of the first embodiment, a lens barrel 23 for positioning the optical imaging lens 1, a module housing unit 24 for positioning the lens barrel 23, a substrate 182 for positioning the module housing unit 24, and an image sensor 181 which is positioned at an image side of the optical imaging lens 1. The image plane 180 is formed on the image sensor 181.

In some other example embodiments, the structure of the filtering unit 170 may be omitted. In some example embodiments, the housing 21, the lens barrel 23, and/or the module housing unit 24 may be integrated into a single component or assembled by multiple components. In some example embodiments, the image sensor 181 used in the present embodiment is directly attached to a substrate 182 in the form of a chip on board (COB) package, and such package is different from traditional chip scale packages (CSP) since COB package does not require a cover glass before the image sensor 181 in the optical imaging lens 1. Aforesaid exemplary embodiments are not limited to this package type and could be selectively incorporated in other described embodiments.

The six lens elements 110, 120, 130, 140, 150, 160 are positioned in the lens barrel 23 in the way of separated by an air gap between any two adjacent lens elements.

The module housing unit 24 comprises a lens backseat 2401 for positioning the lens barrel 23 and an image sensor base 2406 positioned between the lens backseat 2401 and the image sensor 181. The lens barrel 23 and the lens backseat 2401 are positioned along a same axis I-I′, and the lens backseat 2401 is close to the outside of the lens barrel 23. The image sensor base 2406 is exemplarily close to the lens backseat 2401 here. The image sensor base 2406 could be optionally omitted in some other embodiments of the present invention.

Because the length of the optical imaging lens 1 is merely 5.552 mm, the size of the mobile device 20 may be quite small. Therefore, the embodiments described herein meet the market demand for smaller sized product designs.

Reference is now made to FIG. 40, which shows another structural view of a second embodiment of mobile device 20′ applying the aforesaid optical imaging lens 1. One difference between the mobile device 20′ and the mobile device 20 may be the lens backseat 2401 comprising a first seat unit 2402, a second seat unit 2403, a coil 2404 and a magnetic unit 2405. The first seat unit 2402 is close to the outside of the lens barrel 23, and positioned along an axis I-I′, and the second seat unit 2403 is around the outside of the first seat unit 2402 and positioned along with the axis I-I′. The coil 2404 is positioned between the first seat unit 2402 and the inside of the second seat unit 2403. The magnetic unit 2405 is positioned between the outside of the coil 2404 and the inside of the second seat unit 2403.

The lens barrel 23 and the optical imaging lens 1 positioned therein are driven by the first seat unit 2402 for moving along the axis I-I′. The rest structure of the mobile device 20′ is similar to the mobile device 20.

Similarly, because the length of the optical imaging lens 1, 5.552 mm, is shortened, the mobile device 20′ may be designed with a smaller size and meanwhile good optical performance is still provided. Therefore, the present embodiment meets the demand of small sized product design and the request of the market.

According to above illustration, it is clear that the mobile device and the optical imaging lens thereof in example embodiments, through controlling the detail structure and/or reflection power of the lens elements, the length of the optical imaging lens is effectively shortened and meanwhile good optical characters are still provided.

While various embodiments in accordance with the disclosed principles been described above, it should be understood that they are presented by way of example only, and are not limiting. Thus, the breadth and scope of exemplary embodiment(s) should not be limited by any of the above-described embodiments, but should be defined only in accordance with the claims and their equivalents issuing from this disclosure. Furthermore, the above advantages and features are provided in described embodiments, but shall not limit the application of such issued claims to processes and structures accomplishing any or all of the above advantages.

Additionally, the section headings herein are provided for consistency with the suggestions under 37 C.F.R. 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set out in any claims that may issue from this disclosure. Specifically, a description of a technology in the “Background” is not to be construed as an admission that technology is prior art to any invention(s) in this disclosure. Furthermore, any reference in this disclosure to “invention” in the singular should not be used to argue that there is only a single point of novelty in this disclosure. Multiple inventions may be set forth according to the limitations of the multiple claims issuing from this disclosure, and such claims accordingly define the invention(s), and their equivalents, that are protected thereby. In all instances, the scope of such claims shall be considered on their own merits in light of this disclosure, but should not be constrained by the headings herein. 

What is claimed is:
 1. An optical imaging lens, sequencially from an object side to an image side along an optical axis, comprising an aperture stop, first, second, third, fourth, fifth and sixth lens elements, each of said first, second, third, fourth, fifth and sixth lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side, wherein: said object-side surface of said first lens element comprises a convex portion in a vicinity of the optical axis; said image-side surface of said second lens element comprises a convex portion in a vicinity of a periphery of the second lens element; said third lens element has negative refracting power, and said image-side surface thereof comprises a concave portion in a vicinity of a periphery of the third lens element; said image-side surface of said fourth lens element comprises a convex portion in a vicinity of the optical axis; and said image-side surface of said sixth lens element comprises a concave portion in a vicinity of the optical axis and a convex portion in a vicinity of a periphery of the sixth lens element; the optical imaging lens as a whole comprises only the six lens elements having refracting power.
 2. The optical imaging lens according to claim 1, wherein an air gap between the first lens element and the second lens element along the optical axis is AG12, an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, the sum of the thickness of all six lens elements along the optical axis is ALT, and AG12, AG23, AG56 and ALT satisfy the equation: 2.0≦ALT/(AG12+AG23+AG56).
 3. The optical imaging lens according to claim 2, wherein a central thickness of the second lens element along the optical axis is T2, a central thickness of the sixth lens element along the optical axis is T6, and T2 and T6 satisfy the equation: 0.9≦T2/T6.
 4. The optical imaging lens according to claim 2, wherein an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis is AAG, and AG12, AG23, AG45 and AAG satisfy the equation: 2.2≦AAG/(AG12+AG23+AG45).
 5. The optical imaging lens according to claim 4, wherein a central thickness of the second lens element along the optical axis is T2, and T2 and ALT satisfy the equation: ALT/T2≦7.0.
 6. The optical imaging lens according to claim 1, wherein a central thickness of the third lens element along the optical axis is T3, a central thickness of the sixth lens element along the optical axis is T6, and T3 and T6 satisfy the equation: T6/T3≦2.0.
 7. The optical imaging lens according to claim 6, wherein a central thickness of the second lens element along the optical axis is T2, an air gap between the first lens element and the second lens element along the optical axis is AG12, an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, and T2, AG12, AG23 and AG56 satisfy the equation: 0.7≦T2/(AG12+AG23+AG56).
 8. The optical imaging lens according to claim 6, wherein said object-side surface of said sixth lens element comprises a concave portion in a vicinity of the optical axis.
 9. The optical imaging lens according to claim 1, wherein a central thickness of the second lens element along the optical axis is T2, the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis is AAG, and T2 and AAG satisfy the equation: AAG/T2≦5.0.
 10. The optical imaging lens according to claim 9, wherein said object-side surface of said first lens element comprises a concave portion in a vicinity of a periphery of the first lens element.
 11. The optical imaging lens according to claim 1, wherein a central thickness of the first lens element along the optical axis is T1, a central thickness of the second lens element along the optical axis is T2, and T1 and T2 satisfy the equation: T1/T2≦1.5.
 12. The optical imaging lens according to claim 11, wherein an air gap between the first lens element and the second lens element along the optical axis is AG12, an air gap between the third lens element and the fourth lens element along the optical axis is AG34, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, and AG12, AG34, AG45 and AG56 satisfy the equation: 1.0≦AG34/(AG12+AG45+AG56).
 13. The optical imaging lens according to claim 1, wherein a central thickness of the third lens element along the optical axis is T3, an air gap between the first lens element and the second lens element along the optical axis is AG12, an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, and T3, AG12, AG23 and AG45 satisfy the equation: 0.8≦T3/(AG12+AG23+AG45).
 14. The optical imaging lens according to claim 1, wherein an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis is AAG, and AG23, AG45, AG56 and AAG satisfy the equation: 2.0≦AAG/(AG23+AG45+AG56).
 15. The optical imaging lens according to claim 14, wherein said object-side surface of said fifth lens element comprises a concave portion in a vicinity of the optical axis.
 16. The optical imaging lens according to claim 15, wherein a central thickness of the sixth lens element along the optical axis is T6, an air gap between the first lens element and the second lens element along the optical axis is AG12, and T6, AG12, AG23 and AG45 satisfy the equation: 0.9≦T6/(AG12+AG23+AG45).
 17. The optical imaging lens according to claim 1, wherein a central thickness of the third lens element along the optical axis is T3, an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, and T3, AG23, AG45 and AG56 satisfy the equation: 0.7≦T3/(AG23+AG45+AG56).
 18. The optical imaging lens according to claim 1, wherein a central thickness of the sixth lens element along the optical axis is T6, an air gap between the first lens element and the second lens element along the optical axis is AG12, an air gap between the second lens element and the third lens element along the optical axis is AG23, an air gap between the fifth lens element and the sixth lens element along the optical axis is AG56, and T6, AG12, AG23 and AG56 satisfy the equation: 1.0≦T6/(AG12+AG23+AG56).
 19. The optical imaging lens according to claim 18, wherein an air gap between the fourth lens element and the fifth lens element along the optical axis is AG45, the sum of all five air gaps from the first lens element to the sixth lens element along the optical axis is AAG, and AG12, AG45, AG56 and AAG satisfy the equation: 3.0≦AAG/(AG12+AG45+AG56).
 20. A mobile device, comprising: a housing; and a photography module positioned in the housing and comprising: the optical imaging lens as claimed in claim 1; a lens barrel for positioning the optical imaging lens; a module housing unit for positioning the lens barrel; and an image sensor positioned at the image side of the optical imaging lens. 